Automatic nailing machine



April 14, 1959 E. GUE'RRANT AUTOMATIC NAILING MACHINE Filed Oct. 17, 1955 E DMONDS L. GUERRANT A TTORNE Y U ited States Patent AUTOMATIC NAILING MACHINE Edmonds L. Guerrant, Fort Worth, Tex.

Application October 17, 1955, Serial No. 540,896

1 Claim. (Cl. 1-1) This invention relates to automatic nailing machines and has reference to apparatus for nailing lengths of wood one on another, for example, nailing a door stop on a door jamb before the door frame is completed. Nailing, as herein referred to, includes stapling, and pneumatic nailing devices hereinafter referred to include pneumatic stapling devices, either of which may be employed when practicing the invention.

An object of the invention is to provide a machine which will operate automatically once it is started, and turn itself off when the work piece has passed therethrough.

Another object is to provide control means for quickly and easily varying the distance between nails or staples.

A further object is to provide a nailing machine capable of nailing unusually long Work pieces.

These and other objects will become apparent from the following description and accompanying drawing of an exemplary form of the invention, wherein:

Figure l is a side elevation and broken sectional view of a nailing machine embodying the features of the invention.

Figure 2 is a broken perspective view of adjustment means for varying the spacing of nails or staples, together with a portion of the feeding mechanism for moving the work piece through the machine.

Figure 3 is a sectional view taken on line 33 of Figure 1 showing the primary control valve.

Figure 4 is a side elevation of the valve shown in Figure 3 and additionally showing portions of the control pin and a part of the lever for manually operating the pin for stopping the action of the machine, when desired, before the work piece has completely passed therethrough.

Figure 5 is a broken transverse section of the table top and longitudinal opening therein, together with a Work piece supported on the table, a portion of the feeding pawl engaging the work piece, and the lower portion of a nailing device for driving nails into the work.

The form of the invention shown includes a table having legs 11 and a top 12. Lengthwise of the table and near the center thereof there is a longitudinal slot 13 to accommodate a feeding pawl to be described.

In the illustrated form of the invention, the nailing device 14 accommodates staples 15 instead of nails, but as heretofore referred to either nails or staples may be used. The nailing device 14 is supported above the table by brackets, not shown, and is spaced from the surface of the table top 12 to accommodate lengths of wood 16 and 17, one on top of the other, which comprise the work piece 18. Work piece hold downs 19 slidably engage the upper surface of the upper length of wood 16 on opposite sides of the nailing device 14. Since work piece hold downs 19 are conventional, the same are not herein described in detail; however, it is to be understood that the same are preferably spring mounted and arranged so as to normally bear downwardly in sliding contact against the moving work piece 18.

A feature of the invention has to do with a feeding ice pawl assembly 20 for moving the work piece 18 lengthwise of the table 10. The pawl assembly 20 is comprised of parallel pivoted arms 21, similar in arrangement and construction to hell cranks, and have a pointed barb or gripper 22 on the upper end thereof adapted to move through the slot 13 in the table top 12 for engaging the bottom surface of the work piece 18. The feeding pawl arms 21 are pivotally mounted on opposite sides of a longitudinally reciprocating feed rod 23 slidably mounted in supports 24 suspended beneath the table top 12. The last referred to pivotal connection of the arms 21 with the feed rod 23 is by means of a pivot pin 25 which is positioned through said arms and through a mounting block 26 on the feed rod. The lower ends of the feeding pawl arms 21 are pivotally connected with a fitting 27 on the extending end of a piston rod 28. The last referred to pivotal connection is by means of a pin 29 positioned through the arms 21 and block 27. The feeding pawl assembly 20 is prevented from rotation about the axis of the feed rod 23 by means of a cross rod 30 mounted thereon having rollers 31 which contact the upper surfaces of parallel rails 32 mounted on the sides of the table 10. The cross rod 31 is secured to the feed rod 23 by means of a mounting block 33.

An extending end of the cross rod 30 outwardly of its adjacent rail 32 is provided with a fitting 34 supporting a calibrated control bar 35 having spaced depending slidably adjustable fingers 36 mounted thereon.

The feeding pawl 20 is actuated by a pneumatic cylinder 37 mounted beneath the table top 12 by means of a pivotal connection 38 on a depending bracket 39 at one end of the cylinder and a wire link 40 connected with the table top 12 and the cylinders surface at the other end thereof.

Near the center of the table 10 and on the side thereof adjacent the calibrated feed control bar 35 there is a primary control valve 41 rotatably mounted in a depending bracket 42 which, in turn, is secured to a horizontal frame member 43 on the table 10. The control valve 40 is of the rotor type and includes a supply inlet 44, an outlet 45 which is connected with the nailing device 14 by means of a hose 46, an outlet 47 which is connected with a reversing valve 48 by means of a hose 49 and a return inlet 58 which is connected with a T fitting 51 by means of a hose 52. As will become apparent, the return inlet communicates with the outlet 45 which is connected with the nailing device 14 when the machine is set for automatic operation. One of the lines 53 from the reversing valve 48 extends to one end of the cylinder 37, whereas the other line 54 from the reversing valve 48 extends to the heretofore referred to T fitting 51 and thence by a separate hose connection 55 to the remaining end of the cylinder 37. The reversing valve 48 includes an extending handle or lever 56 located between the two depending fingers 36 on the feed control bar 35.

Another feature of the invention has to do with automatic means for stopping automatic action of the feeding pawl after the work piece 18 has moved beyond the nailing device 14. A vertical control pin 57 suitably supported beneath the table top 12 and extending upwardly through a hole, not shown, the latter is normally urged upwardly by means of a compression spring 58 secured to the pin and mounted on the horizontal bracket 43 heretofore described. The lower end of the control pin 57 is provided with a laterally projecting pin 59 for engaging a longitudinal slot 60 in one end of a manual control lever 61. A depending bracket 62 on the table 10 is pivotally connected with the manual control lever 61 by means of a pin 63. The end of the control lever 61 opposite its longitudinal slot 60 is provided with a projecting handle 64. One side of the valve element of the primary control valve 41 is provided with an air valve lever 65 having a projecting pin 66 positioned between laterally projecting pins 67 on the control pin 57 near the lower end of the latter. On the side of the primary control valve 41 opposite the air valve lever 65 there is another lever 68 for manually rotating the case of the primary control valve.

In operation, the primary control valve 41 is set for automatic operation of the machine by means of the manual lever 68. By this arrangement pneumatic pressure is supplied through the inlet 44 in the primary control valve 41 and pressure is supplied through the outlet 47 therein through the hose 49 to the reversing valve 48. By reason of the position of the control lever 56 on the latter, pneumatic pressure is first supplied to the outer end of the pneumatic cylinder 37 through the hose 53. The piston rod 28 then moves outwardly of the cylinder and inwardly of the table and the thrust thereof tlits the feeding pawl assembly 20 upwardly causing the barb '22 to engage the lower surface of the work piece 18 and move it beneath the nailing device 14. During the work piece actuating operation a depending finger 36 on the feed control bar 35 contacts the reversing valve lever 56 and reverses the action of the air cylinder 37. At this time return air from the T-fitting 51 through the line 52 and through the inlet 50 in the primary control valve 41, supplies pneumatic pressure through the valve outlet 45 and through the hose 46 to the nailing device, causing the latter to drive a staple or nail into the work piece 18. The other of the depending fingers 36 then engages the control lever 56 on the reversing valve 48, thus repeating the cycle until the work piece 18 passes beyond the control pin 57; then the pin 57 moves upwardly actuating the air valve lever 65 and stopping the action of the machine. From the latter it will be obvious that the locations of the depending fingers 36 control the stroke of the machine and the distance between staples 15.

The machine may be manually operated when desired by rotating the case of the primary control valve 41 by means of the manual lever 68 in a direction so as to move the vertical control pin 57 downwardly. By means of the handle 64 on the manual control lever 61 the valve 41 may be set in a position whereby the supply inlet 44 is in communication with the outlet 45 and connecting line 46 to the nailing device 14. The nailing device 14 is then operated in the usual manner, as by means of pressing a button 69. Detents in the end of the case of the primary control valve 41 and a spring loaded stop 71 in the depending supporting bracket 43 are provided for carrying out the described rotary positioning of the primary control valve.

The invention is not limited to the exemplary construction herein shown and described, but may be made in various ways within the scope of the appended claim.

What is claimed is:

A feeding mechanism for moving a work piece through a nailing machine including a horizontal work piece supporting surface, said feeding mechanism comprising: a reciprocating rod beneath and parallel with said work piece supporting surface, a feeding pawl pivotally mounted on said reciprocating rod arranged to engage the work piece and move the same on said surface beneath a nailing device, a reciprocating pneumatic cylinder pivotally connected with said feeding pawl and substantially parallel with the direction of movement of said work piece, a source of pneumatic pressure, a reversing valve'connected with said source of pneumatic pressure, and lines extending from said reversing valve to opposite ends of said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,447,490 Shellenberger Mar. 6,1923 2,456,221 Stilwell Dec. 14, 1948 2,612,951 Palmleaf Oct. 7, 1952 2,765,468 Cootes Oct. 9, 1956 

